Re: [petsc-users] Nested Fieldsplit for custom index sets

2017-01-23 Thread Barry Smith
It is "relative" to the level in which you are doing the fieldsplit, it does not go all the way up to the original problem. > On Jan 23, 2017, at 10:22 AM, Hoang Giang Bui wrote: > > Hello > > May I know if the nested IS is identified based on relative local index

Re: [petsc-users] Nested Fieldsplit for custom index sets

2017-01-23 Thread Hoang Giang Bui
Hello May I know if the nested IS is identified based on relative local index or the global one? It's hard to identify that in the attached example. Giang On Thu, Jul 28, 2016 at 10:35 AM, Lawrence Mitchell < lawrence.mitch...@imperial.ac.uk> wrote: > Dear Artur, > > On 28/07/16 02:20, Safin,

Re: [petsc-users] Nested Fieldsplit for custom index sets

2016-08-01 Thread Safin, Artur
-users] Nested Fieldsplit for custom index sets Dear Artur, On 28/07/16 02:20, Safin, Artur wrote: > Barry, Lawrence, > >> I think the SubKSPs (and therefore SubPCs) are not set up until you call >> KSPSetUp(ksp) which your code does not do explicitly and is therefore done >

Re: [petsc-users] Nested Fieldsplit for custom index sets

2016-07-28 Thread Lawrence Mitchell
Dear Artur, On 28/07/16 02:20, Safin, Artur wrote: > Barry, Lawrence, > >> I think the SubKSPs (and therefore SubPCs) are not set up until you call >> KSPSetUp(ksp) which your code does not do explicitly and is therefore done >> in KSPSolve. > > I added KSPSetUp(), but unfortunately the issue

Re: [petsc-users] Nested Fieldsplit for custom index sets

2016-07-27 Thread Safin, Artur
Barry, Lawrence, > I think the SubKSPs (and therefore SubPCs) are not set up until you call > KSPSetUp(ksp) which your code does not do explicitly and is therefore done in > KSPSolve. I added KSPSetUp(), but unfortunately the issue did not go away. I have created a MWE that replicates the

Re: [petsc-users] Nested Fieldsplit for custom index sets

2016-07-27 Thread Lawrence Mitchell
> On 27 Jul 2016, at 03:54, Safin, Artur wrote: > > Barry, > >> Do you have a call to KSPSetFromOptions() before the call >> PCFieldSplitGetSubKSP()? I am guessing not which means that the PC does not >> yet know that it is of type fieldplit. > > Yes, I call

Re: [petsc-users] Nested Fieldsplit for custom index sets

2016-07-26 Thread Safin, Artur
Barry, > Do you have a call to KSPSetFromOptions() before the call > PCFieldSplitGetSubKSP()? I am guessing not which means that the PC does not > yet know that it is of type fieldplit. Yes, I call KSPSetFromOptions() for the global matrix at the beginning of the code. Should I also do it for

Re: [petsc-users] Nested Fieldsplit for custom index sets

2016-07-26 Thread Barry Smith
Do you have a call to KSPSetFromOptions() before the call PCFieldSplitGetSubKSP()? I am guessing not which means that the PC does not yet know that it is of type fieldplit. Barry > On Jul 26, 2016, at 9:00 PM, Safin, Artur wrote: > > Hello all, > > I would like

[petsc-users] Nested Fieldsplit for custom index sets

2016-07-26 Thread Safin, Artur
Hello all, I would like to work out how to get nested fieldsplit to work correctly. I have a submatrix (labeled fieldsplit_P) that I would like to block precondition with sub-blocks A & B. To do this, I access the PC object within fieldsplit_P, and pass index sets corresponding to these